Well, you made a family announcement that she didn't receive well, who knows why. She obviously needed additional time to warm up to the idea. Now that she has, leave it be. Confronting her about it will accomplish... what?

I agree with the above.

I burst into tears - scared, worried, OMG tears when I got that little blue line with our third (and only unplanned) pregnancy. I would be upset if I thought my DH harbored resentment because that news caught me by surprise and my first thoughts were to be worried, not excited. I certainly came around and very quickly. But, her initial reaction, while unfortunately public, isn't a big deal. How she handles it with the new baby is what is important.